This invention pertains to dynamic earth anchors, or rock stabilizing fixtures, as the same are also identified, and in particular to such earth anchor so conceived as to facilitate either the insertion of a rock bolt-receiving sleeve into the terrestrial formation borehole, or the insertion of the rock bolt into the sleeve, as well as to sleeves of and for such earth anchors.
Dynamic earth anchors, or rock stabilizing fixtures, are well known. Exemplary thereof is the "Dynamic Rock Stabilizing Fixture" set forth the Reissue U.S. Pat. No. 32645 and issued to James J. Scott.
The fixture in the aforesaid patent comprises a sleeve having a hollow body which is inserted into the end of a terrestrial borehole, and a rock bolt which is then inserted into the borehole-seated sleeve. Typically, the bolt will have threads or other disruptions on the surface thereof to enhance its fast engagement with the sleeve. The combination sets up an almost immediate restraint of the terrestrial formation, and accommodates a roof plate, or the like, at the formation face.
Due to discontinuities and/or asperities in the sleeve-receiving borehole, it is frequently difficult to set the sleeve into the termination of the borehole; too, difficulties are commonly encountered in inserting the rock bolt into the seated sleeve.
The foregoing illustrates limitations known to exist in present devices. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully described hereinafter.